This application note introduces a method to enable DBS analysis of basic drugs on Agilent Bond Elut Dried Matrix Spotting (DMS) cards, which is achieved by optimizing desorption conditions.
This document describes a method to improve the sensitivity of quantitative bioanalysis for basic drugs using Dried Matrix Spotting (DMS) technology combined with LC/MS/MS. It specifically evaluates the performance of Agilent Bond Elut Dried Matrix Spotting cards, which utilize a noncellulose-based substrate, for analyzing four beta-blockers: atenolol, pindolol, metoprolol, and propranolol.
The study investigates various desorption variables, including centrifugation time, solvent composition (methanol vs. acetonitrile), and formic acid concentration. Results indicate that centrifuging punched spots for 15 minutes yields optimal recovery and response, particularly for hydrophobic analytes like propranolol. Additionally, specific solvent ratios, such as 60% acetonitrile with 0.1% formic acid, were found to maximize sensitivity for certain compounds compared to traditional 80% methanol protocols.
| Column | Agilent Poroshell 120 EC-C18, 30 x 2.1 mm, 2.7 ym |
|---|---|
| Run time | 3 min |
| Gas temperature | 350 C |
| Sheath gas temperature | 250 C |
| Capillary voltage | 4,000 V |
| Polarity | Positive |
Centrifuging the sample for 15 minutes gave the best overall results, especially for the more hydrophobic analyte, propranolol.
Atenolol yields the best response at 60% ACN:0.1% FA or 40% MeOH:0.1% FA.
For pindolol, 60% ACN:0.1% FA generated the best response.